If the plastic lugs have broken off on your Zanussi oven (may apply to your AEG or Electrolux Ovens too) when you have tried to take the door apart here is how to fix them:
You drill a small hole into the plastic bracket on the outside door where the lug has broken off. I use a 2mm drill bit. Then screw in a small screw to fit the hole. So a 2.2mm self tapping screw. You have now created a new lug and the door will go back together. This takes about 5 minutes with the right tools.
You put the door back together and then you drill up from the bottom of the door through the lugs. You can use a larger drill bit this time and put in large self tapping screws. This creates a solid fix on the door. I haven't done this method myself but it too will only be a 5 minute job with the right tools.Google+